## Secure shell client and server policy. ####################################### ## ## The per user domain template for the ssh module. ## ## ##

## This template creates a derived domains which are used ## for ssh client sessions and user ssh agents. A derived ## type is also created to protect the user ssh keys. ##

##

## This template is invoked automatically for each user, and ## generally does not need to be invoked directly ## by policy writers. ##

##
## ## The prefix of the user domain (e.g., user ## is the prefix for user_t). ## # template(`ssh_per_userdomain_template',` ############################## # # Declarations # type $1_home_ssh_t; #, $1_file_type; files_type($1_home_ssh_t) role $1_r types $1_ssh_t; type $1_ssh_t; #, nscd_client_domain; domain_type($1_ssh_t) type $1_ssh_agent_t; domain_type($1_ssh_agent_t) role $1_r types $1_ssh_agent_t; ############################## # # $1_ssh_t local policy # allow $1_ssh_t self:capability { setuid setgid dac_override dac_read_search }; allow $1_ssh_t self:process ~{ ptrace setcurrent setexec setfscreate setrlimit execmem dyntransition }; allow $1_ssh_t self:fd use; allow $1_ssh_t self:fifo_file { read getattr lock ioctl write append }; allow $1_ssh_t self:unix_dgram_socket { create ioctl read getattr write setattr append bind connect getopt setopt shutdown }; allow $1_ssh_t self:unix_stream_socket { create ioctl read getattr write setattr append bind connect getopt setopt shutdown listen accept }; allow $1_ssh_t self:unix_dgram_socket sendto; allow $1_ssh_t self:unix_stream_socket connectto; allow $1_ssh_t self:shm { associate getattr setattr create destroy read write lock unix_read unix_write }; allow $1_ssh_t self:sem { associate getattr setattr create destroy read write unix_read unix_write }; allow $1_ssh_t self:msgq { associate getattr setattr create destroy read write enqueue unix_read unix_write }; allow $1_ssh_t self:msg { send receive }; allow $1_ssh_t self:tcp_socket { create connect ioctl read getattr write setattr append bind getopt setopt shutdown }; # Transition from the user domain to the derived domain. domain_auto_trans($1_t, ssh_exec_t, $1_ssh_t) # Read the ssh key file. allow $1_ssh_t sshd_key_t:file r_file_perms; # Access the ssh temporary files. allow $1_ssh_t sshd_tmp_t:dir create_dir_perms; allow $1_ssh_t sshd_tmp_t:file create_file_perms; files_create_tmp_files($1_ssh_t, sshd_tmp_t, { file dir }) # for rsync allow $1_ssh_t $1_t:unix_stream_socket rw_socket_perms; allow $1_ssh_t $1_t:unix_stream_socket connectto; # user can manage the keys and config allow $1_t $1_home_ssh_t:dir rw_dir_perms; allow $1_t $1_home_ssh_t:file create_file_perms; allow $1_t $1_home_ssh_t:lnk_file create_lnk_perms; allow $1_t $1_home_ssh_t:sock_file create_file_perms; # ssh client can manage the keys and config allow $1_ssh_t $1_home_ssh_t:file create_file_perms; allow $1_ssh_t $1_home_ssh_t:lnk_file { getattr read }; # ssh servers can read the user keys and config allow ssh_server $1_home_ssh_t:dir r_dir_perms; allow ssh_server $1_home_ssh_t:lnk_file r_file_perms; allow ssh_server $1_home_ssh_t:file r_file_perms; kernel_read_kernel_sysctl($1_ssh_t) corenet_tcp_sendrecv_all_if($1_ssh_t) corenet_raw_sendrecv_all_if($1_ssh_t) corenet_tcp_sendrecv_all_nodes($1_ssh_t) corenet_raw_sendrecv_all_nodes($1_ssh_t) corenet_tcp_sendrecv_all_ports($1_ssh_t) corenet_tcp_bind_all_nodes($1_ssh_t) dev_read_urand($1_ssh_t) fs_getattr_all_fs($1_ssh_t) fs_search_auto_mountpoints($1_ssh_t) # run helper programs - needed eg for x11-ssh-askpass corecmd_exec_shell($1_ssh_t) corecmd_exec_bin($1_ssh_t) domain_use_wide_inherit_fd($1_ssh_t) files_list_home($1_ssh_t) files_read_usr_files($1_ssh_t) files_read_etc_runtime_files($1_ssh_t) files_read_etc_files($1_ssh_t) libs_use_ld_so($1_ssh_t) libs_use_shared_libs($1_ssh_t) logging_send_syslog_msg($1_ssh_t) logging_read_generic_logs($1_ssh_t) miscfiles_read_localization($1_ssh_t) seutil_read_config($1_ssh_t) sysnet_read_config($1_ssh_t) userdom_use_unpriv_users_fd($1_ssh_t) tunable_policy(`use_dns',` allow $1_ssh_t self:udp_socket { create ioctl read getattr write setattr append bind getopt setopt shutdown connect }; corenet_udp_sendrecv_all_if($1_ssh_t) corenet_udp_sendrecv_all_nodes($1_ssh_t) corenet_udp_sendrecv_dns_port($1_ssh_t) corenet_udp_bind_all_nodes($1_ssh_t) ') tunable_policy(`use_nfs_home_dirs',` fs_manage_nfs_dirs($1_ssh_t) fs_manage_nfs_files($1_ssh_t) ') tunable_policy(`use_samba_home_dirs',` fs_manage_cifs_dirs($1_ssh_t) fs_manage_cifs_files($1_ssh_t) ') # for port forwarding tunable_policy(`user_tcp_server',` corenet_tcp_bind_ssh_port($1_ssh_t) ') optional_policy(`nis.te',` nis_use_ypbind($1_ssh_t) ') ifdef(`TODO',` allow $1 sbin_t:dir r_dir_perms; allow $1 sbin_t:notdevfile_class_set r_file_perms; if (read_default_t) { allow $1 default_t:dir r_dir_perms; allow $1 default_t:notdevfile_class_set r_file_perms; } # Read /var. allow $1_ssh_t var_t:dir r_dir_perms; allow $1_ssh_t var_t:notdevfile_class_set r_file_perms; # Read /var/run, /var/log. allow $1_ssh_t var_run_t:dir r_dir_perms; allow $1_ssh_t var_run_t:{ file lnk_file } r_file_perms; can_kerberos($1_ssh_t) allow $1_ssh_t $1_tmp_t:dir r_dir_perms; # Access the users .ssh directory. file_type_auto_trans({ sysadm_ssh_t $1_ssh_t }, $1_home_dir_t, $1_home_ssh_t, dir) file_type_auto_trans($1_ssh_t, $1_home_dir_t, $1_home_ssh_t, sock_file) allow sysadm_ssh_t $1_home_ssh_t:file create_file_perms; allow sysadm_ssh_t $1_home_ssh_t:lnk_file { getattr read }; dontaudit $1_ssh_t $1_home_t:dir { getattr search }; # for /bin/sh used to execute xauth dontaudit $1_ssh_t proc_t:dir search; dontaudit $1_ssh_t proc_t:{ lnk_file file } { getattr read }; # Inherit and use descriptors from gnome-pty-helper. ifdef(`gnome-pty-helper.te', `allow $1_ssh_t $1_gph_t:fd use;') # Write to the user domain tty. allow $1_ssh_t $1_tty_device_t:chr_file { read write getattr ioctl }; allow $1_ssh_t devpts_t:dir { read search getattr }; allow $1_ssh_t $1_devpts_t:chr_file { read write getattr ioctl }; # allow ps to show ssh can_ps($1_t, $1_ssh_t) ifdef(`xserver.te', ` # Communicate with the X server. ifdef(`startx.te', ` can_unix_connect($1_ssh_t, $1_xserver_t) allow $1_ssh_t $1_xserver_tmp_t:sock_file rw_file_perms; allow $1_ssh_t $1_xserver_tmp_t:dir search; ')dnl end if startx ifdef(`xdm.te', ` allow $1_ssh_t { xdm_xserver_tmp_t xdm_tmp_t }:dir search; allow $1_ssh_t { xdm_tmp_t }:sock_file write; ') ')dnl end if xserver #allow ssh to access keys stored on removable media # Should we have a boolean around this? files_search_mnt($1_ssh_t) r_dir_file($1_ssh_t, removable_t) ifdef(`xdm.te', ` # should be able to remove these two later allow $1_ssh_t xdm_xserver_tmp_t:sock_file { read write }; allow $1_ssh_t xdm_xserver_tmp_t:dir search; allow $1_ssh_t xdm_xserver_t:unix_stream_socket connectto; allow $1_ssh_t xdm_xserver_t:shm r_shm_perms; allow $1_ssh_t xdm_xserver_t:fd use; allow $1_ssh_t xdm_xserver_tmpfs_t:file read; allow $1_ssh_t xdm_t:fd use; ')dnl end if xdm.te ') dnl endif TODO ############################## # # $1_ssh_agent_t local policy # allow $1_ssh_agent_t self:process setrlimit; allow $1_ssh_agent_t self:capability setgid; allow $1_ssh_agent_t { $1_ssh_agent_t $1_t }:process signull; allow $1_ssh_t $1_ssh_agent_t:unix_stream_socket connectto; domain_auto_trans($1_t, ssh_agent_exec_t, $1_ssh_agent_t) kernel_read_kernel_sysctl($1_ssh_agent_t) dev_read_urand($1_ssh_agent_t) dev_read_rand($1_ssh_agent_t) fs_search_auto_mountpoints($1_ssh_agent_t) domain_use_wide_inherit_fd($1_ssh_agent_t) files_read_etc_files($1_ssh_agent_t) files_read_etc_runtime_files($1_ssh_agent_t) libs_read_lib($1_ssh_agent_t) libs_use_ld_so($1_ssh_agent_t) libs_use_shared_libs($1_ssh_agent_t) logging_send_syslog_msg($1_ssh_agent_t) miscfiles_read_localization($1_ssh_agent_t) if (use_nfs_home_dirs) { fs_manage_nfs_files($1_ssh_agent_t) } if (use_samba_home_dirs) { fs_manage_cifs_files($1_ssh_agent_t) } optional_policy(`nis.te',` nis_use_ypbind($1_ssh_agent_t) ') ifdef(`TODO',` # Write to the user domain tty. access_terminal($1_ssh_agent_t, $1) # Allow the user shell to signal the ssh program. allow $1_t $1_ssh_agent_t:process signal; # allow ps to show ssh can_ps($1_t, $1_ssh_agent_t) allow $1_ssh_agent_t proc_t:dir search; dontaudit $1_ssh_agent_t proc_t:{ lnk_file file } { getattr read }; dontaudit $1_ssh_agent_t selinux_config_t:dir search; # Access the ssh temporary files. Should we have an own type here # to which only ssh, ssh-agent and ssh-add have access? allow $1_ssh_agent_t $1_tmp_t:dir r_dir_perms; file_type_auto_trans($1_ssh_agent_t, tmp_t, $1_tmp_t) # for ssh-add can_unix_connect($1_t, $1_ssh_agent_t) # transition back to normal privs upon exec domain_auto_trans($1_ssh_agent_t, { bin_t shell_exec_t $1_home_t }, $1_t) allow $1_ssh_agent_t bin_t:dir search; allow $1_ssh_agent_t bin_t:lnk_file read; if (use_nfs_home_dirs) { domain_auto_trans($1_ssh_agent_t, nfs_t, $1_t) } if (use_samba_home_dirs) { domain_auto_trans($1_ssh_agent_t, cifs_t, $1_t) } allow $1_ssh_agent_t { home_root_t $1_home_dir_t }:dir search; allow $1_ssh_t $1_tmp_t:sock_file write; ifdef(`xdm.te', ` allow $1_ssh_agent_t xdm_t:fd use; allow $1_ssh_agent_t xdm_t:fifo_file { read write }; # kdm: sigchld allow $1_ssh_agent_t xdm_t:process sigchld; ') # # Allow command to ssh-agent > ~/.ssh_agent # allow $1_ssh_agent_t $1_home_t:file rw_file_perms; allow $1_ssh_agent_t $1_tmp_t:file rw_file_perms; # Allow the ssh program to communicate with ssh-agent. allow $1_ssh_t $1_tmp_t:sock_file write; allow $1_ssh_t $1_t:unix_stream_socket connectto; allow $1_ssh_t sshd_t:unix_stream_socket connectto; ') dnl endif TODO ') ####################################### ## ## The template to define a ssh server. ## ## ##

## This template creates a domains to be used for ## creating a ssh server. This is typically done ## to have multiple ssh servers of different sensitivities, ## such as for an internal network-facing ssh server, and ## a external network-facing ssh server. ##

##
## ## The prefix of the server domain (e.g., sshd ## is the prefix for sshd_t). ## # template(`ssh_server_template', ` type $1_t, ssh_server; #, nscd_client_domain; role system_r types $1_t; type $1_devpts_t; term_login_pty($1_devpts_t) type $1_var_run_t; files_pid_file($1_var_run_t) allow $1_t self:capability { kill sys_chroot sys_resource chown dac_override fowner fsetid setgid setuid sys_tty_config }; allow $1_t self:fifo_file rw_file_perms; allow $1_t self:process { signal setsched setrlimit setexec }; allow $1_t self:tcp_socket { listen accept create connect ioctl read getattr write setattr append bind getopt setopt shutdown }; allow $1_t self:udp_socket { connect create ioctl read getattr write setattr append bind getopt setopt shutdown }; allow $1_t $1_devpts_t:chr_file { rw_file_perms setattr getattr relabelfrom }; term_create_pty($1_t,$1_devpts_t) allow $1_t $1_var_run_t:file create_file_perms; files_create_pid($1_t,$1_var_run_t,file) can_exec($1_t, sshd_exec_t) # Access key files allow $1_t sshd_key_t:file { getattr read }; kernel_read_kernel_sysctl($1_t) corenet_tcp_sendrecv_all_if($1_t) corenet_udp_sendrecv_all_if($1_t) corenet_raw_sendrecv_all_if($1_t) corenet_tcp_sendrecv_all_nodes($1_t) corenet_udp_sendrecv_all_nodes($1_t) corenet_raw_sendrecv_all_nodes($1_t) corenet_udp_sendrecv_all_ports($1_t) corenet_tcp_sendrecv_all_ports($1_t) corenet_tcp_bind_all_nodes($1_t) corenet_udp_bind_all_nodes($1_t) dev_read_urand($1_t) fs_dontaudit_getattr_all_fs($1_t) selinux_get_fs_mount($1_t) selinux_validate_context($1_t) selinux_compute_access_vector($1_t) selinux_compute_create_context($1_t) selinux_compute_relabel_context($1_t) selinux_compute_user_contexts($1_t) auth_dontaudit_read_shadow($1_t) auth_domtrans_chk_passwd($1_t) auth_rw_login_records($1_t) auth_rw_lastlog($1_t) corecmd_read_bin_symlink($1_t) # for sshd subsystems, such as sftp-server. corecmd_getattr_bin_file($1_t) domain_wide_inherit_fd($1_t) domain_subj_id_change_exempt($1_t) domain_role_change_exempt($1_t) domain_obj_id_change_exempt($1_t) files_read_etc_files($1_t) files_read_etc_runtime_files($1_t) init_rw_script_pid($1_t) libs_use_ld_so($1_t) libs_use_shared_libs($1_t) logging_search_logs($1_t) logging_send_syslog_msg($1_t) miscfiles_read_localization($1_t) seutil_read_default_contexts($1_t) sysnet_read_config($1_t) userdom_search_all_users_home($1_t) tunable_policy(`use_nfs_home_dirs',` fs_read_nfs_files($1_t) ') tunable_policy(`use_samba_home_dirs',` fs_read_cifs_files($1_t) ') optional_policy(`inetd.te',` tunable_policy(`run_ssh_inetd',` allow $1_t self:process signal; files_list_pids($1_t) ',` corenet_tcp_bind_ssh_port($1_t) init_use_fd($1_t) init_use_script_pty($1_t) ') ',` # These rules should match the else block # of the run_ssh_inetd tunable directly above corenet_tcp_bind_ssh_port($1_t) init_use_fd($1_t) init_use_script_pty($1_t) ') optional_policy(`mount.te', ` mount_send_nfs_client_request($1_t) ') ifdef(`TODO',` # Read /var. allow $1_t var_t:dir getattr; allow $1_t home_dir_type:dir getattr; dontaudit sshd_t userpty_type:chr_file relabelfrom; ') dnl end TODO ') ######################################## ## Read ssh server keys ## ## The type of the process performing this action. ## # interface(`ssh_dontaudit_read_server_keys',` gen_require(` type sshd_key_t; class file { getattr read }; ') dontaudit $1 sshd_key_t:file { getattr read }; ')